It is conventional in the art to stack containers in tiers for shipping, handling and display. Tiers of the containers are separated by conventional tier sheets which support and separate a plurality of tiers of the containers forming a stack of the containers. The stack of containers is usually held together by conventional strapping, e.g. metal or plastic strapping, and/or conventional plastic wrap.
It is also conventional that a stack of containers be placed in a retail outlet and that customers remove containers from that stack for purchase. This is typically done, for example, with canned goods or soft drink bottles in food stores, particularly soft drink bottles of larger sizes, e.g. 16 oz. or 18 oz. or one liter or two liter sizes. With such display, as the containers are removed from the stack, the tier sheets are simply removed from the stack to present a new tier of containers for purchase.
Such tiered stacks of containers are also assembled by manufacturers of the containers for shipping empty containers to others for placing contents in the containers. In this case, usually, the containers do not have a closure. For example, the containers may be a bottle with a threaded mouth but no cap thereon, where the cap is placed on the bottle after filling.
Whether the tiered stack of containers is empty, e.g., assembled by the manufacturer of the container for shipment to others, or filled, e.g., by a manufacturer who fills the container and applies the closure, these stacks encounter fairly rough handling during in plant movement and long distance transit. Generally, the first tier of the stack is placed on a conventional pallet, and subsequent tiers of containers are separated by tier sheets, as noted above. The stacked pallet is configured to be moved on a conveyor or by a conventional forklift, during manufacture, filling or distribution. Such movement by a conveyor or forklift and the like cause considerable forces to be applied to the stack of containers, and it is very typical that during such handling, some of those containers in the tiered stack are displaced from the stack. Once the stack is wrapped with a plastic wrap and strapped with conventional strapping, the stack is fairly secure and few containers are displaced.
The displacement of containers from a stack, prior to strapping and wrapping the stack with plastic film is a particularly difficult problem to solve. Even with relatively gentle handling, e.g., with a forklift or with a conveyor line, it is not unusual for a number of containers to be displaced from the stack, and those containers must be hand inserted back into the stack, which is labor intensive and a discontinuity in the manufacturing process.
There have been several attempts in the art to mitigate this problem, and, basically, these attempts involve providing edges of the tier sheet in the form of a generally vertically disposed wall portion for impeding lateral movement of the containers in the stack. For example, U.S. Pat. No. 2,928,200 shows edge portions of a tier sheet being folded downwardly to restrain the tops of bottles, or other containers, in a lower tier. U.S. Pat. No. 4,638,941 shows edge portions of the tier sheet being folded into a wall portion which likewise functions to retain the containers in a tiered stack. However, these approaches are relatively expensive because they involve substantial modification and reconfiguration of the tier sheet. While these approaches are commercially used for some containers, the expense thereof makes them impractical for many other containers.
Accordingly, it would be of a substantial advantage to the art to provide a tier sheet, which can impede lateral movement of an outside container disposed at an outside row of a tiered stack of containers such as to prevent that container from being displaced from the stack during handling of the stack. Additionally, the tier sheet can be produced at a very low expense, making the tier sheet generally useful for all types of stacks of containers.